Japanese Patent Publication Nos. 45(1970)-11149 (corresponding to U.S. Pat. No. 3,697,275), 47(1972)-20741 (corresponding to U.S. Pat. No. 3,687,667) and 49(1974)-10697, and Japanese Patent Provisional Publication Nos. 57(1982)-138632 and 58(1983)-169143 describe image-forming methods comprising exposing to light a light-sensitive material which comprises a light-sensitive layer containing silver halide, a reducing agent and a polymerizable compound provided on a support. In these image-forming methods, when the exposed silver halide is developed using a developing solution, the polymerizable compound is caused to polymerize in the presence of a reducing agent (which is oxidized) to form a polymer image. Thus, these methods need a wet development process employing a developing solution. Therefore the process takes a relatively long time for its operation.
An improved image-forming method employing a dry process is described in Japanese Patent Provisional Publication Nos. 61(1986)-69062 and 61(1986)-73145 (the contents of both publications are described in U.S. Pat. No. 4,629,676 and European Patent Provisional Publication No. 0174634A2). In this image-forming method, a recording material (i.e., light-sensitive material) comprising a light-sensitive layer containing a light-sensitive silver salt (i.e., silver halide), a reducing agent, a cross-linkable compound (i.e., polymerizable compound) and a binder provided on a support is imagewise exposed to light to form a latent image, and then the material is heated to polymerize within the area where the latent image of the silver halide has been formed. The above method employing the dry process and the light-sensitive material employable for such method are also described in Japanese Patent Provisional Publication Nos. 61(1986)-183640, 61(1986)-188535 and 61(1986)-228441.
The above-mentioned image-forming methods are based on the principle in which the polymerizable compound is polymerized within the area where a latent image of the silver halide has been formed.
Further, Japanese Patent Provisional Publication No. 61(1986)-260241 describes an image-forming method in which the polymerizable compound within the area where a latent image of the silver halide has not been formed is polymerized. In this method, when the material is heated, the reducing agent functions as polymerization inhibitor within the area where a latent image of the silver halide has been formed, and the polymerizable compound within the other area (unexposed area) is polymerized.
Japanese Patent Provisional Publications Nos. 61(1986)-275742 and 61(1986)-278849 describe examples of the light-sensitive materials, which employ microcapsules containing at least two components of the light-sensitive layer, that is polymerizable compound and a color image forming substance. The light-sensitive material having such a structure has an advantage of giving an image of high quality.
The light-sensitive layer is prepared by arranging microcapsules containing the above-mentioned components on a support. In the preparation of the light-sensitive material, when a continuous light-sensitive material is rolled or cut into a desired length, a surface of the light-sensitive material is damaged by contact or friction with other material, whereby the microcapsules are ruptured. In the image-forming method utilizing the light-sensitive material, the light-sensitive material is developed by heating simultaneously with or after the imagewise exposure to obtain a latent image, and then is pressed on an image-receiving material to transfer the latent image onto the image-receiving material. When the light-sensitive material having the ruptured capsules is utilized for the above described image-forming method, a white background area of the transferred image is stained (i.e., smudged) by insufficiently cured polymerizable compound. Accordingly, the clearness of the obtained image lowers.
The above-mentioned problem is also observed in the use of the conventional pressure-sensitive and heat-sensitive recording materials. In the use of these conventional recording materials, various methods have been proposed to solve the problem. For instance, methods employing fine particles of starch or the like (i.e., antismudging agent) are described in Japanese Patent Publication No. 47(1972)-1178 (corresponding to British Pat. No. 1,232,347). A method employing hollow resin particles having thermal expansion property is described in Japanese Patent Provisional Publication No. 48(1973)-32013 (corresponding to U.S. Pat. No. 3,867,169). A method employing a polyolefin fine powder is described in Japanese Patent Provisional Publication No. 54(1979)-51611 (corresponding to British Pat. No. 200,681). A method employing a cellulose fine powder is described in Japanese Patent Provisional Publication No. 60(1985)-224581.
The present inventor has found that the above-mentioned methods employing the fine particles or the powder in combination with the microcapsules in the light-sensitive material show an advantage in preventing the smudging. However, according to study of the inventor, in the case that the unpolymerized polymerizable compound of the light-sensitive material is transferred to the image-receiving material, an optical density of the image is apt to lower.